Add dedicated `serve_web_viewer` function

[emilk]

We have two function for serving data in our SDK:

• serve_grpc (Add serve_grpc API #9447)
• serve_web

serve_grpc starts a gRPC server and uses it as a log sink. Makes sense.

serve_web also starts a gRPC server AND a web server. This makes less sense.

I suggest we go with one of these alternatives instead:

❌ Integrate serve_web into serve_grpc

rr.serve_grpc() # Only starts the gRPC server

rr.serve_grpc(host_web_viewer=True) # Also hosts the web viewer

# Also opens a browser with the web viewer, connected to the gRPC server
rr.serve_grpc(host_web_viewer=True, open_browser=True)

PRO:

• one single function
• always a log sink
• can't host a web viewer without a gRPC server

CON:

• can't host a web viewer without a gRPC server
• one function, two features

✅ Replace serve_web with serve_web_viewer ← We're going with this one!

Separate function for orthogonal things:

grpc_uri = rr.serve_grpc() # Hosts the gRPC server
rr.serve_web_viewer(connect_to=grpc_uri) # Hosts a web viewer

PRO:

• two functions for two features
• you can access all four quadrants of the cartesian feature product

CON:

• there is little value in just hosting a web viewer without a gRPC server
• confusingly, serve_grpc is a log sink but serve_web_viewer is not
• open_browser param would probably have to go, or blindly guess on the gRPC ip/port.

❌ Integrate both functions into a common serve function

rr.serve(grpc=True) # Only host gRPC server
rr.serve(viewer=True) # Only host web viewer
rr.serve(grpc=True, viewer=True) # Host both
rr.serve() # Error: must choose at least one thing to serve

PRO:

• one single function, with a clear name
• you can access all four quadrants of the cartesian feature product

CON:

• its only a sink of grpc=True
• one function for two features
• there is little value in just hosting a web viewer without a gRPC server

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I think any of these alternatives will be less confusing to our users, but I think the first alternative is probably the best.

In either case, we keep the old serve_web (and even older serve), but deprecated.

[emilk]

Let's keep the rr.serve_web() as is for 0.23, but deprecate it for Rerun 0.24:

• Deprecate serve_web #9541

But we'll already migrate all docs to only point to the new serve_web_viewer function.